Post-Exercise Potassium Flux and Exercise Intensity

N.L. Coplan, G. Gleim, M. Scandura, E. Fisher, J. Nicholas

Exercise intensity above which lactate begins to rise is associated with a significant rise in plasma potassium (K). In this study, we assessed the effect of exercise intensity on post-exercise K flux. K at base, peak exercise, 2 min recovery (2R), and 5 min recovery (5R) from subjects with peak lactate >4 mM/1 (A, n=9) and those with <4 mM/L (8, n=6) were compared.

           K (meq/l), mean (+/- sem)
          baseline    PEAK        2R         5R
Group A   3.8 (.1)   4.9 (.1)   3.9 (.1)   3.7 (.1)
Group B   4.0 (.1)   4.5 (.1)   4.3 (.1)   4.0 (.1)

There was no significant difference in exercise duration (10+.8 vs 9+1 min). Delta-K from base-peak and peak-2A was greater in A than B (p<.01). Delta-K in the 2R-5R interval was similar in both.

Conclusion: K flux in the immediate recovery period is influenced by exercise intensity, as assessed by peak lactate. This may be important for evaluating exercise-related arrhythmia.

Med. Sci. Sports Exerc. 19(2):s, 1987.